Systems and methods for determining the usability of person support apparatuses

ABSTRACT

A person support apparatus includes a support adapted to support thereon an occupant of the person support apparatus and a sensor configured to detect an ambient air characteristic. The sensor generates an output signal based on the detected characteristic and communicates the output signal to a controller. The controller is configured to receive the output signal from the sensor and determine a usability status of the person support apparatus. The usability status may include an indication that the person support apparatus is ready for use by an occupant, whether a potential hazard exists for an occupant of the person support apparatus, a cleaning status of the person support apparatus, or a location of the person support apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 62/398,577 filed Sep. 23, 2016, by inventor Marko Kostic et al.and entitled SYSTEMS AND METHODS FOR DETERMINING THE USABILITY OF PERSONSUPPORT APPARATUSES, and U.S. non-provisional patent application Ser.No. 15/709,586, filed Sep. 20, 2017, by inventor Marko Kostic et al. andentitled SYSTEMS AND METHODS FOR DETERMINING THE USABILITY OF PERSONSUPPORT APPARATUSES, the complete disclosures of both of which areincorporated herein by reference.

BACKGROUND

The present disclosure relates to systems and methods for determiningand communicating the usability status of person support apparatuses,non-limiting examples of which include beds, cots, stretchers,recliners, chairs, operating tables, and the like.

Infection control is a concern in most healthcare facilities. Equipmentused with patients must be cleaned and made suitable for use with eachpatient. The cleaning of person support apparatuses typically involvesthe use of cleaning solvents. However, some cleaning solvents may leavea residue that could present a problem for certain patients, such asthose with respiratory issues or allergies. In some cases, the personsupport apparatuses are brought to a particular location within thefacility for cleaning. However, it can be challenging to monitor andtrack the usability status of individual person support apparatuses,particularly within a healthcare facility having a multitude of suchperson support apparatuses.

SUMMARY

In its various embodiments, the present disclosure provides systems andmethods to monitor, track, provide feedback and/or train a userregarding a usability status of a person support apparatus.

In one embodiment, a person support apparatus is provided that includesa support adapted to support thereon an occupant of the person supportapparatus. A sensor detects an ambient air characteristic and generatesan output signal based on the detected characteristic. A controller isconfigured to receive the output signal from the sensor and determine ausability status of the person support apparatus based on the outputsignal.

In one aspect, the usability status indicates whether the person supportapparatus is ready for use by an occupant. In another aspect, theusability status indicates whether a potential hazard exists for anoccupant of the person support apparatus having a compromised healthstatus. The compromised health status may relate to an occupant'srespiratory status, allergy status, or other medical status.

In another aspect, the usability status indicates a cleaning status ofthe person support apparatus. The cleaning status indicates if theperson support apparatus has been cleaned or not cleaned. In anotheraspect, the cleaning status indicates if the person support apparatushas been sufficiently cleaned, insufficiently cleaned, or not cleaned.

In another embodiment, the sensor is adapted to detect volatile organiccompounds associated with a cleaning agent used to clean the personsupport apparatus. The sensor may further be configured to detect atleast one additional ambient air characteristic and to use theadditional ambient air characteristic to determine the usability status.In one example, the at least one additional ambient air characteristicis a pressure of the air and the controller is adapted to determine afloor of a building on which the person support apparatus is locatedbased upon the pressure of the air. In another aspect, the controller isfurther adapted to compare a current location of the person supportapparatus with a location of a cleaning area within the building todetermine if they correspond or not.

In yet another embodiment, the sensor comprises at least two of avolatile organic compound (VOC) sensor, a humidity sensor, anatmospheric pressure sensor, and a temperature sensor. The controller isconfigured to compare the output signal to reference data stored in amemory accessible by the controller in order to determine the usabilitystatus. In some embodiments, the reference data includes a predeterminedcleaning profile of the detected characteristic over time. In oneexample, the predetermined cleaning profile specifies a minimumconcentration of volatile organic compounds over a time period, thevolatile organic compounds associated with a cleaning agent used toclean the person support apparatus. In another example, the cleaningprofile further specifies a predetermined humidity over a time period.In some embodiments, the reference data is communicated to the personsupport apparatus from an off-board device. The reference data may beconfigurable by a user of the person support apparatus.

The person support apparatus further includes an indicator, in someembodiments, that is in communication with the controller. The indicatorindicates a usability status of the person support apparatus.

In any of the embodiments, the person support apparatus may be one of abed, a stretcher, a table, a cot, a chair, or the like.

In other embodiments, the person support apparatus further includes asecond sensor adapted to detect a second ambient air characteristic andgenerate a second output signal based on the detected characteristic.The controller determines the usability status based on a combination ofthe outputs from the two sensors. In other embodiments, the two sensorsare each adapted to detect multiple ambient air characteristics and thecontroller determines the usability status based upon a combination ofall of the multiple ambient air characteristics detected by the twosensors.

According to another aspect, a pressure sensor is mounted relative tothe support. The pressure sensor detects a contact pressure applied tothe support by a person, such as a cleaning person, and generates anoutput signal based on the detected pressure. The controller uses theoutput signals from the sensor and the pressure sensor to determine theusability status of the person support apparatus.

According to another embodiment, a person support apparatus is providedthat includes a support, first and second sensors, and a controller. Thesupport is adapted to support thereon an occupant of the person supportapparatus. The first sensor is adapted to detect a first ambient aircharacteristic and to generate a first output signal based on thedetected first characteristic. The second sensor is adapted to detect asecond ambient air characteristic and to generate a second output signalbased on the detected second characteristic. The controller determines ausability status of the person support apparatus based on the firstoutput signal and the second output signal.

In one aspect, the first sensor is adapted to detect volatile organiccompounds associated with a cleaning agent used to clean the personsupport apparatus. In another aspect, one of the first or seconddetected characteristics is a pressure of the air, and the controlleruses the detected air pressure to determine a floor of a building onwhich the person support apparatus is located.

In another embodiment, the first sensor includes a volatile organiccompound sensor and the first output signal is indicative of aconcentration of volatile organic compounds in the atmosphere adjacentthe person support apparatus. The second sensor includes a humiditysensor and the second output signal is indicative of a humidity of theatmosphere adjacent the person support apparatus.

In still another embodiment, the first sensor is configured to detect afirst compound (or first class of compounds) and the second sensor isconfigured to detect a second and different compound, (or second anddifferent class of compounds). The controller determines the usabilitystatus based upon reference data indicating a minimum concentration ofthe first compound (or class of compounds) over time and a minimumconcentration of the second compound (or class of compounds) over time.

According to another embodiment, a method of determining a usabilitystatus of a person support apparatus is provided. The method includesproviding a sensor to detect an ambient air characteristic. The sensorgenerates an output signal based on the detected characteristic and ausability status of the person support apparatus is determined based onthe output signal. The usability status is indicated to a user.

In one aspect, the method includes using the sensor to detect at leastone additional ambient air characteristic and to use the additionalambient air characteristic to determine the usability status. In anexample, the additional ambient air characteristic is a pressure of theair.

In another embodiment, the method includes using a second sensor todetect a second ambient air characteristic and generate a second outputsignal based on the detected characteristic. The determination of theusability status is based on a combination of the output signal and thesecond output signal.

A display is included in some embodiments that is adapted to display anambient air pressure sensed by an ambient air pressure sensor on boardthe person support apparatus. In some embodiments, the controller issuesan alert if the ambient air pressure passes a threshold. Alternatively,or additionally, the controller uses an output of the ambient airpressure sensor to determine a floor of a building in which the personsupport apparatus is currently located. In another aspect, thecontroller monitors the ambient air pressure repetitively and analyzesthe repetitive ambient air pressure readings to differentiate weatherrelated changes in ambient air pressure from elevation related changesin ambient air pressure.

Before the various embodiments disclosed herein are explained in detail,it is to be understood that the claims are not to be limited to thedetails of operation, to the details of construction, or to thearrangement of the components set forth in the following description orillustrated in the drawings. The embodiments described herein arecapable of being practiced or being carried out in alternative ways notexpressly disclosed herein. Also, it is to be understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including” and “comprising” and variations thereof is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items and equivalents thereof. Further, enumeration may beused in the description of various embodiments. Unless otherwiseexpressly stated, the use of enumeration should not be construed aslimiting the claims to any specific order or number of components. Norshould the use of enumeration be construed as excluding from the scopeof the claims any additional steps or components that might be combinedwith or into the enumerated steps or components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a person supportapparatus according to one aspect of the present disclosure;

FIG. 2 is a diagram of an embodiment of a control system usable with theperson support apparatus of FIG. 1;

FIG. 3 is a schematic illustration of a portion of the person supportapparatus of FIG. 1 showing a sensor detecting volatile organiccompounds;

FIG. 4 is a flow chart of an algorithm that may be used by the controlsystem for determining a usability status of the person supportapparatus;

FIG. 5 is a flow chart of an alternative algorithm that may be used bythe control system for determining the usability status of the personsupport apparatus;

FIG. 6 is a graph of an illustrative cleaning profile that may be usedby the control system for determining the usability status of the personsupport apparatus;

FIG. 7 is a graph of another illustrative cleaning profile that may beused by the control system for determining the usability status of theperson support apparatus; and

FIG. 8 is a flow chart of yet another algorithm that may be used by thecontrol system for determining the usability status of the personsupport apparatus.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An illustrative person support apparatus 20 that may incorporate one ormore aspects of the present disclosure is shown in FIG. 1. Although theparticular form of person support apparatus 20 illustrated in FIG. 1 isa bed adapted for use in a hospital or other medical setting, it will beunderstood that person support apparatus 20 could, in differentembodiments, be a cot, a stretcher, a gurney, a recliner, an operatingtable, a residential bed, or any other structure capable of supporting aperson, whether stationary or mobile and/or whether medical orresidential. The embodiments herein relate to determining andcommunicating a usability status of person support apparatus 20.Non-limiting examples of the usability status of person supportapparatus 20 include an indication that person support apparatus 20 isready for use by an occupant, whether a potential hazard exists for anoccupant of the person support apparatus 20 having a compromised healthstatus, a cleaning status of person support apparatus 20, and a locationof person support apparatus 20 within a building in which person supportapparatus 20 is located.

In general, person support apparatus 20 includes a base 22 having aplurality of wheels 24, a pair of lifts 26 supported on the base, alitter frame 28 supported on lifts 26, and a support deck 30 supportedon litter frame 28. Person support apparatus 20 further includes aheadboard (not shown), a footboard 34, and a plurality of siderails 36.Siderails 36 are all shown in a raised position in FIG. 1 but are eachindividually movable to a lowered position in which ingress into, andegress out of, person support apparatus 20 is not obstructed by loweredsiderails 36.

Lifts 26 are adapted to raise and lower litter frame 28 with respect tobase 22. Lifts 26 may be hydraulic actuators, electric actuators, or anyother suitable device for raising and lowering litter frame 28 withrespect to base 22. In the illustrated embodiment, lifts 26 are operableindependently so that the tilting of litter frame 28 with respect tobase 22 can also be adjusted. That is, litter frame 28 includes a headend 38 and a foot end 40, each of whose height can be independentlyadjusted by the nearest lift 26. Person support apparatus 20 is designedso that when an occupant lies thereon, his or her head will bepositioned adjacent head end 38 and his or her feet will be positionedadjacent foot end 40.

Litter frame 28 provides a structure for supporting support deck 30, theheadboard, footboard 34, and siderails 36. Support deck 30 provides asupport surface for a mattress (not shown in FIG. 1), or other softcushion, so that a person may lie and/or sit thereon. The top surface ofthe mattress or other cushion forms a support surface for the occupant.Support deck 30 is made of a plurality of sections, some of which arepivotable about generally horizontal pivot axes. In the embodiment shownin FIG. 1, support deck 30 includes a head section 42, a seat section44, a thigh section 46, and a foot section 48. Head section 42, which isalso sometimes referred to as a Fowler section, is pivotable about agenerally horizontal pivot axis between a generally horizontalorientation (not shown in FIG. 1) and a plurality of raised positions(one of which is shown in FIG. 1). Thigh section 46 and foot section 48may also be pivotable about generally horizontal pivot axes.

Unless indicated otherwise, the mechanical construction of personsupport apparatus 20 may be the same as, or nearly the same as, themechanical construction of the Model 3002 S3 bed manufactured and soldby Stryker Corporation of Kalamazoo, Mich. This mechanical constructionis described in greater detail in the Stryker Maintenance Manual for theMedSurg Bed, Model 3002 S3, published in 2010 by Stryker Corporation ofKalamazoo, Mich., the complete disclosure of which is incorporatedherein by reference. It will be understood by those skilled in the artthat person support apparatus 20 can be designed with other types ofmechanical constructions, such as, but not limited to, those describedin commonly assigned, U.S. Pat. No. 7,690,059 issued to Lemire et al.,and entitled HOSPITAL BED; and/or commonly assigned U.S. Pat.Publication No. 2007/0163045 filed by Becker et al. and entitled PATIENTHANDLING DEVICE INCLUDING LOCAL STATUS INDICATION, ONE-TOUCH FOWLERANGLE ADJUSTMENT, AND POWER-ON ALARM CONFIGURATION, the completedisclosures of both of which are also hereby incorporated herein byreference. The mechanical construction of person support apparatus 20may also take on forms different from what is disclosed in theaforementioned references.

Person support apparatus 20 may include an exit detection system (notshown) that is adapted to determine when an occupant, such as, but notlimited to, a patient, of person support apparatus 20 is likely to exitperson support apparatus 20. Such an exit detection system is adapted todetermine when an occupant is likely to leave prior to the occupantactually leaving, and to issue an alert and/or notification toappropriate personnel so that proper steps can be taken in response tothe occupant's imminent departure in a timely fashion. The particularstructural details of the exit detection system can vary widely. In oneembodiment, the exit detection system is constructed and functions inthe manner disclosed in commonly assigned U.S. Pat. No. 5,276,432 issuedto Travis and entitled PATIENT EXIT DETECTION MECHANISM FOR HOSPITALBED, the complete disclosure of which is incorporated herein byreference.

Still referring to FIG. 1, person support apparatus 20 also includes oneor more sensors 50 mounted to siderails 36 for detecting one or moreambient air characteristics. The exact number and location of sensors 50can vary. For example, one or more sensors 50 can be mounted to each ofthe siderails 36 and optionally the headboard and/or footboard 34.Additional sensors 50 may optionally be mounted to support deck 30.Sensors 50 are spaced evenly about a perimeter of support deck 30 orclustered in one or more locations around support deck 30. Each sensor50 is configured to detect one or more ambient air characteristics.Sensors 50 are mounted to person support apparatus 20 using any suitablemechanical or non-mechanical fastener, non-limiting examples of whichinclude an adhesive, clamps, screws, a snap-fit frame, etc. In someembodiments, sensors 50 are built directly into the components of personsupport apparatus 20 and are integral therewith.

Referring now to FIG. 2, person support apparatus 20 includes a controlsystem 54 that is configured to monitor, track, provide feedback and/ortrain a user regarding a usability status of person support apparatus20. Control system 54 includes a controller 58 that is constructed ofany electrical component, or group of electrical components, that arecapable of carrying out the functions described herein. In manyembodiments, controller 58 is a conventional microcontroller, althoughnot all such embodiments need include a microcontroller. In general,controller 58 includes any one or more microprocessors,microcontrollers, field programmable gate arrays, systems on a chip,volatile or nonvolatile memory, discrete circuitry, and/or otherhardware, software, or firmware that is capable of carrying out thefunctions described herein, as would be known to one of ordinary skillin the art. Such components can be physically configured in any suitablemanner, such as by mounting them to one or more circuit boards, orarranging them in other manners, whether combined into a single unit ordistributed across multiple units. The instructions followed bycontroller 58 in carrying out the functions described herein, as well asthe data necessary for carrying out these functions, are stored in amemory 60 that is accessible by controller 58.

A user interface 62 communicates with controller 58 and enables a userof person support apparatus 20 to control one or more aspects of personsupport apparatus 20 and optionally receive information regarding astatus of person support apparatus 20. User interface 62 is implementedin the embodiment shown in FIG. 1 as a control panel having a lid(flipped down in FIG. 1) underneath which is positioned a plurality ofcontrols. The controls—which may be buttons, dials, switches, or otherdevices—allows a user to move the various components of person supportapparatus 20, as well as control other aspects of person supportapparatus 20. User interface 62 may also include a display fordisplaying information regarding a usability status of person supportapparatus 20. Although FIG. 1 illustrates user interface 62 mounted tofootboard 34, it will be understood that user interface 62 can bepositioned elsewhere, and/or that one or more additional user interfacescan be added to person support apparatus 20 in different locations, suchas siderails 36.

Referring again to FIG. 2, control system 54 includes a transceiver 64for enabling communication between controller 58 and a network server66. Transceiver 64 communicates with server 66 through a hard wiredconnection and/or a wireless connection. In some embodiments,transceiver 64 communicates with network server 66 using Wi-Ficommunications, Bluetooth and/or ZigBee communications, or otherprotocols. Network server 66 is adapted to communicate with a remoteinterface 68, such as a personal computer, tablet, or smart device.Remote interface 68 may include a display for displaying informationregarding a usability status of person support apparatus 20.

Control system 54 follows one or more algorithms for determining theusability status of person support apparatus 20. Three of thesedifferent algorithms are illustrated in FIGS. 4, 5, and 8. Thesealgorithms monitor, track, provide feedback and/or train a userregarding a usability status of person support apparatus 20. Whenfollowing the algorithms, control system 54 may stamp informationregarding the usability status to create a time log of the date and timeregarding the determination of the usability status. The usabilitystatus may be based on one or more target thresholds or reference datathat varies based on standards and protocols related to the use ofperson support apparatus 20 and/or based on an occupant using orscheduled to use person support apparatus 20. The standards, protocols,thresholds, and/or reference data are selectable by an appropriateperson, such as a healthcare provider, either locally at person supportapparatus 20 or at remote interface 68. The standards, protocols,thresholds, and/or reference data are also updatable from time to timewhen needed or upon request.

Control system 54 is also configured to send notifications regarding theusability status, either through user interface 62 and/or remoteinterface 68 regarding the usability status. Control system 54 is alsoconfigurable to save information, such as login information, usabilitystatus determinations, and data from sensors 50 for tracking and/oranalysis purposes. In this manner, control system 54 allows a healthcarefacility or other provider to analyze, track, and/or monitor informationregarding when person support apparatus is ready for use by an occupant,when potential hazards exist for certain occupants, cleaning status(e.g. when and whether person support apparatus 20 was cleaned or notcleaned), and location information related to person support apparatus20.

User interface 62 and/or remote interface 68 may include controls anddisplays for one-way and/or two-way communication with a user regardingthe usability status of person support apparatus 20. In one example,user interface 62 includes one or more controls (e.g. buttons, switches)or a touch screen that allows a user to initiate a usability statusdetermination process. In another example, user interface 62 includesilluminable status icons, colored lights, and/or a display screen whichcommunicate information regarding the usability of person supportapparatus 20 to a user. Optionally, the usability status information isrelayed to remote interface 68, which includes illuminable status icons,colored lights, and/or a display screen, in addition to or as analternative to user interface 62. For example, usability statusinformation indicating that person support apparatus 20 is ready for useor is cleaned or safe for use may be indicated by illuminating a greenlight or illuminable text or graphics, while a red light or illuminabletext or graphics may be used to indicate person support apparatus 20 isnot ready for use, has not been cleaned or is not safe for use. Inanother example, usability status is communicated using audible signals,such as an alarm indicating person support apparatus 20 is not cleanedor not ready for use. Information regarding usability status isdetermined and displayed in real-time and/or is saved for later analysisand/or display. It will be understood that control system 54 may beconfigured such that various aspects regarding usability status may becommunicated through one or both of user interface 62 and/or remoteinterface 68 as desired in real-time and/or upon request.

Still referring to FIG. 2, each sensor 50 is a multifunctional sensorhaving multiple individual sensors 50 a-d that detect different ambientair characteristics of the atmosphere adjacent person support apparatus20. Each sensor 50 can include more than or less than the fourindividual sensors 50 a-d shown in FIG. 2, depending on the intendeduse. In one embodiment, rather than providing multiple multifunctionalsensors 50 on person support apparatus 20, one or more of the individualsensors 50 a-d can be mounted to person support apparatus 20.Non-limiting examples of suitable individual sensors include a chemicalsensor 50 a, a humidity sensor 50 b, an ambient air pressure sensor 50c, and a temperature sensor 50 d. Chemical sensor 50 a is adapted todetect one or more chemicals associated with a cleaning agent used toclean person support apparatus 20, such as volatile organic compounds, amarker chemical, or a fragrance. Humidity sensor 50 b, ambient airpressure sensor 50 c, and temperature sensors 50 d detect the humidity,air pressure, and temperature of the ambient air adjacent to personsupport apparatus 20. As will be discussed in greater detail below,sensors 50 a-d are positioned on person support apparatus 20 atlocations where they will be able to detect changes in the ambient airdue to the normal evaporation of one or more cleaning agents used toclean person support apparatus 20.

One example of a sensor suitable for use as the sensor 50 is anintegrated environmental sensor available from BOSCH Sensortech ofReutlingen, Germany, such as its BME680 integrated sensor. The BME680sensor is capable of detecting gas, including VOCs, atmosphericpressure, humidity, and temperature. The BMBE680 is a pre-calibratedsensor that is provided with its own software package, which isoptionally used with any of the algorithms described herein fordetermining the usability status. Additional examples of integratedsensors include the BME280 form BOSCH Sensortech, which is capable ofdetecting pressure, humidity, and temperature. An example of a suitablechemical sensor 50 a includes microsensor resistor arrays, such as thosedescribed in Li et al., “Volatile Organic Compound Discrimination usingNanostructured Polythiophene Sensors,” IEEE, p. 191-194, 2005. Anotherexample is a nanowire-based VOC sensor, such as those described in Baum,“Nanowire-based Sensors Offer Improved Detection of Volatile OrganicCompounds,” NIST Tech Beat, 2011 (web). Still other types of sensors maybe used.

Optionally, one or more additional sensors 70 are mounted to personsupport apparatus 20 to provide additional information regarding personsupport apparatus 20. In one embodiment, sensor 70 is a pressure sensorconfigured to detect contact pressure applied to one or more surfaces ofperson support apparatus 20 in the manner disclosed in commonly assignedU.S. Pat. Publication No. 2016/0148485 filed by Hayes et al. andentitled SYSTEM AND METHOD OF MANAGING THE CLEANING OF A MEDICALAPPARATUS, the complete disclosure of which is incorporated herein byreference.

Sensors 50 and 70 are communicably coupled to controller 58 to provideinformation from sensors 50 and 70 to controller 58 and to optionallyreceive information from controller 58. Controller 58 is coupled to thesensors 50 and 70 either through a wired or wireless connection. Sensors50 detect the ambient air characteristics mentioned above (VOC's,pressure, humidity, and temperature) and output signals based on thedetected characteristics to controller 58. Controller 58 includes thenecessary programming to determine a usability status of person supportapparatus 20 based on the output signals received from sensors 50 andoptionally sensor 70. In some embodiments, controller 58 communicatesthe data received from the signals to a controller remote from personsupport apparatus 20, such as a controller in a personal computer,tablet, or smart device, which includes the software applications todetermine a usability status of person support apparatus 20 based on theoutput signals received from sensors 50 and optionally sensor 70. Inother embodiments, controller 58 performs the processing of the outputsfrom sensors 50 and/or 70 to determine the usability status of personsupport apparatus 20. Regardless of whether the usability processing isperformed locally on person support apparatus 20 or remotely, theusability status of person support apparatus 20 based on output signalsreceived from the sensors 50 (and in some cases sensor 70) isdetermined, and shared with appropriate personnel.

Referring to FIG. 3 sensors 50 are mounted to siderails 36 adjacentsupport deck 30 such that sensors 50 are capable of detecting aircharacteristics of the air in the vicinity of support deck 30. During acleaning process, a cleaning solution is applied by a cleaning person tosupport deck 30. As the cleaning solution dries, one or more componentsof the cleaning solution, such as a volatile organic compound, evaporateinto the atmosphere adjacent support deck 30 and siderail 36, affectingthe characteristics of the ambient air adjacent sensor 50. Sensor 50detects a presence and/or a concentration of the volatile organiccompound in the atmosphere and provides an output signal to controller58 indicative of the presence and/or concentration of the volatileorganic compound. Sensor 50 also detects additional characteristics ofthe ambient air, such as the humidity, air temperature, and/or airpressure, which are used to provide additional information regarding thecleaning solution used and/or the usability status of person supportapparatus 20. As will be discussed more below, controller 58 records theoutput signals from sensors 50 a-d over a time period and uses therecorded values to determine the usability status of person supportapparatus 20.

Referring now to FIG. 4, control system 54 executes a usabilityalgorithm 100 depicted therein that determines the usability status ofperson support apparatus 20. Algorithm 100 may be implemented insoftware, hardware, or a combination of software and hardware. Whenimplemented with software, algorithm 100 may take on the form of a thinclient application, a fat client application, or a local clientapplication. Thin client applications communicate with one or morenetwork services, which are available on one or more remote networks,such as a healthcare facility network and/or the Internet, and thenetwork services perform bulk of the processing. Thick clientapplications also communicate with one or more network services, but thebulk of the processing is done locally. In some embodiments, controller58 is configured to support both thick and thin client applications, aswell as applications that are purely local.

Algorithm 100 begins with step 102. The commencement of algorithm 100 atstep 102 may occur automatically, or it may occur manually in responseto a user activating a control on person support apparatus 20, such as abutton, icon, switch, lever, etc. It also may commence in response to auser activating a control on a remote device, such as a smart phone,personal computer, nurses' station, etc., that is in communication withperson support apparatus 20 via transceiver 64. In one example,algorithm 100 is manually initiated by a user responsible for cleaningperson support apparatus 20 just prior to beginning the cleaning processto provide the user with information regarding whether or not thecleaning process has been performed properly and/or whether there areany additional concerns following the cleaning process, such as apotential risk to a future occupant having a compromised health status.When configured to start automatically, algorithm 100 may be running anytime person support apparatus 20 has a source of electrical power, or itmay commence after one or more of the following events: the exitdetection system (if included on person support apparatus 20) detectsthat there is no occupant of person support apparatus 20; the patientassigned to person support apparatus 20 is discharged from thecorresponding medical facility; a message is sent from a network serviceor application via transceiver 64; data stored regarding a particularpatient assigned to person support apparatus 20 is deleted from thememory of person support apparatus 20 via user interface 62; and/orother events.

After usability algorithm 100 is initiated, ambient air characteristicsensors 50 a-d, and optionally pressure sensor 70, are activated at step104 to begin collecting information regarding one or more ambient aircharacteristics. With respect to the embodiment of FIG. 2, this includeschemical sensor 50 a detecting a presence and/or a concentration of oneor more volatile organic compounds (or classes of compounds), humiditysensor 50 b detecting a humidity of the atmosphere, ambient air pressuresensor 50 c detecting the atmospheric pressure, and temperature sensor50 d detecting the air or surface temperature. In another example,person support apparatus 20 includes only one type of sensor, such asVOC compound sensor 50 a, or a sub-combination of sensors, such aschemical sensor 50 a and humidity sensor 50 b. One or more of thesensors 50 a-d, controller 58, or both include a clock for measuring oneor more of the ambient air characteristics over time.

At step 106, sensors 50 a-d output a signal indicative of thecorresponding ambient air characteristic to controller 58. The samplingtime and sampling rate of sensors 50 a-d is set based on thecharacteristics of each sensor 50 a-d and the data needed fordetermining the usability status from the output signals. Controller 58utilizes the output signals received from sensors 50 a-d at 108 todetermine the usability status of person support apparatus 20. In oneembodiment, algorithm 100 compares the output signals received from oneor more of sensors 50 a-d with reference data stored in memory 60. Theformat of the reference data is based on the type of informationprovided by sensor 50 a-d. In one example, the reference data is in theform of a predetermined cleaning profile of the detected characteristic,such as the concentration of volatile organic compounds over apredetermined period of time or the concentration of volatile organiccompounds compared to the measured humidity. In another example, thereference data is in the form of a data look-up table includingpredetermined ambient air characteristics or ranges of ambient aircharacteristics that correspond to a particular outcome. In someembodiments, a data look-up table is used to compare the ambient airpressure detected by sensor 50 c with air pressure data corresponding toa particular floor in a building in which person support apparatus 20 islocated.

In some embodiments, one or more components of the reference data arestored in a memory of an off-board device that is communicativelycoupled to controller 58, such as through server 66, rather than inmemory 60 on board person support apparatus 20. The reference data ispre-programmed but configurable by a user. Changing of the referencedata is carried out via user interface 62 and/or via remote interface68. In some embodiments, controller 58 communicates the sensor signalsto a remove device, (e.g. a computer associated with remote interface68) which compares the sensor signals to the reference data, determinesusability status of person support apparatus 20, and then communicatesthe usability status back to person support apparatus 20.

The usability status of person support apparatus 20 may refer to thecleaning status and/or the air quality status of person supportapparatus 20. When referring to the cleaning status, the usabilitystatus may refer to any one or more of the following: whether personsupport apparatus 20 has been cleaned or not; whether person supportapparatus 20 has been sufficiently cleaned or insufficiently cleaned;and whether person support apparatus 20 is in the process of beingcleaned (e.g. a cleaning agent has been applied, but insufficient timehas passed for proper disinfection to have occurred). when referring tothe air quality status, the usability status refers to whether apotential health hazard exists for an occupant of person supportapparatus 20 having a compromised health status (e.g. asthma, allergies,etc.), or whether a potential health hazard exits for an occupant whodoes not have a compromised health status. The usability status—bothcleaning related and air quality related—is determined at step 108 ofalgorithm 100. However, in some embodiments, algorithm 100 is modifiedto only determine one status, such as cleaning or air quality, and notboth.

In general, the cleaning status is determined by comparing the amount orconcentration of detected volatile organic compounds to a thresholdlevel (included within the above-mentioned reference data) anddetermining whether the threshold has been exceeded for a minimum amountof time. The detected VOC corresponds to one or more VOCs that areassociated with the cleaning agents commonly used to clean personsupport apparatus 20, and/or one or more cleaning agents that arespecifically used at the healthcare facility in which person supportapparatus 20 is located. Further discussion of how this cleaning statusis determined is provided below with respect to the description of FIG.6.

In general, the air quality status if determined by comparing thecurrent amount of VOCs detected to one or more thresholds that are partof the above-mentioned reference data. The thresholds are associatedwith VOC levels that may cause discomfort to a person having acompromised health status and/or VOC levels that are known or believedto be harmful to such individuals. The air quality status determinationat step 108 may also compare the currently detected VOC levels tothresholds that correspond to individuals who do not have a compromisedhealth status. Further discussion of how the air quality status ofperson support apparatus 20 is determined is provided below with respectto FIG. 7.

As used herein, the term “cleaning” encompasses any one of more of thefollowing: removing, degrading, and/or otherwise breaking down unwantedmatter on surfaces of person support apparatus 20, treating surfaces ofperson support apparatus 20 by the application of one or more cleaningagents, and/or disinfecting surfaces of person support apparatus 20. Theterm disinfecting is used herein to encompass killing, destroying,inhibiting growth and reproduction, and/or otherwise rendering innocuousbiological organisms, such as bacteria, protists, fungus and mites, forexample, and/or infectious agents, such viruses and prions. It isunderstood that a degree or level of disinfecting is based on severalfactors, non-limiting examples of which include a type of cleaning agentused and a time of treatment with a cleaning agent.

At step 110, controller 58 outputs a signal indicative of the usabilitystatus (cleaning status, air quality status, and/or both) of personsupport apparatus 20. That signal, as indicated by step 112, updatesand/or changes an indicator regarding the usability status of personsupport apparatus 20. In one example, the output signal activates alight and/or generates a sound coming from user interface 62. In anotherexample, the output signal illuminates one or more status icons, coloredlights, and/or a display screen on user interface 62. In still anotherexample, the output signal is transmitted via transceiver 64 to remoteinterface 68, which updates and/or changes information displayablethereon regarding the usability status of person support apparatus 20.As noted, remote interface 68 may be a nurse call station or ahealthcare facility network or some other type of infrastructure thatprovides alerts to personnel interested in the status of person supportapparatus 20. Information regarding the usability status of personsupport apparatus 20 may be displayed locally or remotely in a real-timeto a user. In some embodiments, the usability status is forwarded byalgorithm 100 to a network service that stores the data to allow loggingof and/or analysis of the data. In one example, the usability statusinformation is stored and accessed when needed to determine theusability status of a particular person support apparatus 20 prior touse by an occupant.

When indicating the usability status of person support apparatus 20 atstep 112, some embodiments of person support apparatus 20 includemultiple indicators that are used for indicating different aspects ofperson support apparatus 20. For example, a first indicator may indicatethe cleaning status of person support apparatus 20 while a secondindicator may indicate the air quality status of person supportapparatus 20. In such situations, person support apparatus 20 may reportdifferent usability statuses of person support apparatus 20 at differenttimes. For example, when a cleaning agent is first applied to personsupport apparatus 20, controller 58 may determine the VOX levels are toohigh for someone with compromised health, and therefore active anindicator that indicates the person support apparatus 20 is notcurrently safe for use with certain individuals. At the same time, theVOC levels may not have been detected for a long enough time period tosatisfy the cleaning standards, so controller 58 may active anotherindicator that indicates that person support apparatus 20 has not beencleaned. When the cleaning is finished, controller 58 may change thisindicator to indicate that person support apparatus 20 is cleaned.However, the indicator of undesired air quality for certain individualsmay still be activated, depending upon the VOC levels, and may continueto be activated for as long as it takes for those VOC levels todissipate.

In some embodiments, person support apparatus 20 includes a “lastcleaned on” identifier that is display on user interface 62. In suchembodiments, controller 58 automatically updates this indicator when itdetects VOC levels associated with a cleaner that are of sufficientlyhigh concentration for a predetermined time period so as to indicatethat person support apparatus 20 has been cleaned, as will be discussedmore below. In some of such embodiments, controller 58 does not providea “dirty” or “not cleaned” indication, but instead may simply includethe date of last cleaning, while in others of such embodiments,controller 58 provides both the date of last cleaning and the currentcleaning status.

Referring now to FIG. 5, an alternative exemplary algorithm 200 fordetermining a usability status based on outputs from chemical sensor 50a is illustrated. In this example, chemical sensor 50 a detects andoutputs a signal indicative of a concentration and/or presence of agroup of VOCs or a particular VOC. Following initiation of algorithm 200at step 202 (which is initiated in any of the same manners discussedabove with respect to the initiation of algorithm 100), chemical sensor50 a is activated to begin detecting the presence and/or theconcentration of VOCs in the ambient air at 204. The VOCs are associatedwith one or more cleaning agents used to clean person support apparatus20. Chemical sensor 50 a therefore detects a presence of at least oneVOC in the ambient air that is associated with the cleaning agents beingused. Alternatively or additionally, chemical sensor 50 a detects aconcentration of total VOCs or a particular VOC associated with thecleaning agents being used. In one example, multiple VOC sensors 50 aare used that each detect a particular VOC that is associated with thecleaning agents being used.

At step 206, chemical sensor 50 a outputs a signal indicative of thedetected VOCs in the ambient air. The output signal is indicative ofeither the presence or a concentration of the detected VOCs. Chemicalsensor 50 a optionally includes a clock that allows chemical sensor 50 ato output a signal of the detected presence or concentration of VOCsover time or controller 58 includes a clock for recording the incomingoutput signal from chemical sensor 50 a over time.

The output signal indicative of the detected VOCs is compared at step208 with reference stored in memory 60 of controller 58. Alternatively,the output signal is communicated to server 66 for comparison withreference data stored in a memory accessible to server 66. In oneembodiment, the reference data includes a predetermined cleaning profilethat specifies a minimum concentration of the detected VOCs over a timeperiod.

An exemplary cleaning profile 300 is illustrated in FIG. 6 for use byalgorithms 100 and/or 200 as the reference data for comparison with theoutput signal at steps 108 and/or 208. The cleaning profile 300 includesa predetermined minimum concentration of VOCs over a time period thatcorresponds to a particular usability status, such as a cleaned status,which is illustrated by zone 302. Both VOC concentration and time atthat VOC concentration affect the degree to which the surface iscleaned. The minimum concentration and time period corresponding to acleaned status is determined based on empirical data or other cleaningstandards. The empirical data or other standard data corresponds totreatments at given concentrations of VOCs that yield desired degrees ofcleaning. Different data may be used for different cleaning agents orsolutions.

Controller 58 receives the output signal from chemical sensor 50 aindicative of a concentration of VOCs and compares the concentration tothe zone 302. If the concentration of VOCs is at or above theconcentration defined by zone 302 for the length of time defined by zone302, as illustrated by curve 304, controller 58 outputs a signal at 210indicating a cleaned or satisfactorily cleaned status. If theconcentration of VOCs satisfies the concentration defined by zone 302,but does not stay above that concentration for the length of timedefined by zone 302, as illustrated by curve 306, controller 58 outputsa signal at 210 indicating an uncleaned or unsatisfactorily cleanedstatus. In such situations, controller 58 may be programmed to send amessage to the cleaner, or the cleaning department, indicating that theperson support apparatus 20 should be re-cleaned.

Curve 308 illustrates a scenario in which a high concentration of VOCsis detected from the cleaning agent used to treat person supportapparatus 20, but that high concentration is not maintained for longenough to satisfactorily clean the surface. That is, if theconcentration of VOCs satisfies the desired minimum concentrationdefined by zone 302, but the concentration is not maintained for thelength of time defined by zone 302, as illustrated by curve 308,controller 58 outputs a signal at step 210 indicating an uncleaned orunsatisfactorily cleaned status.

Controller 58 may also analyze the detected concentration of VOCs todetermine if person support apparatus 20 is safe for use by an occupant,and optionally, whether person support apparatus 20 is safe for use byan occupant having a compromised health status. If the concentration ofVOCs indicated by curve 308 is higher than an air quality referencethreshold, controller 58 outputs a signal at step 210 indicating thatperson support apparatus 20 is not safe for use by an occupant, orspecifically that person support apparatus is not safe for an occupanthaving a compromised health status. In one example, the VOCconcentration threshold corresponds to a threshold that is deemedhazardous or potentially hazardous for any occupant. Additionally, oralternatively, the VOC concentration threshold corresponds to athreshold that is deemed hazardous or potentially hazardous for anoccupant having a compromised health status. For example, the VOCconcentration threshold for an occupant having respiratory challenges oran allergy to certain cleaning agents is lower than the VOCconcentration threshold for an occupant without such health issues.

When detecting the air quality status of person support apparatus 20,controller 58 automatically repeats the detection and analysis steps(e.g. steps 104-110, 204-210) so that when the detected VOCconcentrations have dissipated to below the threshold air qualitythresholds, controller 58 will detect this. In response to detectingthat the air quality has improved to the level of being safe for anoccupant, controller 58 proceeds to step 212 (or step 112 for algorithm100) and updates a status indicator regarding the air quality status ofperson support apparatus 20. In this manner, potential users of personsupport apparatus 20 are automatically notified when the VOC levelsassociated with person support apparatus 20 have dissipated sufficientlyto meet the corresponding air quality standard. As noted previously, theair quality standards can be configured by authorized personnel so thathealthcare facilities can customize the standards to their ownpreferences.

The output signal generated at step 210 activates a visual and/oraudible indicator at step 212. The activation of the indicator(s) mayoccur in any of the same manners discussed above with respect to step112 of algorithm 100. Non-limiting examples of the types of indicatorsinclude illuminable status icons, colored lights, and/or a displayscreen on user interface 62 and/or remote interface 68, the latter ofwhich receives information regarding the usability status of personsupport apparatus 20 from controller 58. In one example, the cleaningindicator is a colored light or colored icon on a display, such as red,green, and yellow, that communicates to a user that person supportapparatus 20 is not cleaned (red indicator lit), cleaned or sufficientlycleaned (green indicator lit), or is insufficiently cleaned or cleaningneeds to be extended/repeated (yellow indicator lit). In anotherexample, an air quality status indicator includes an alarm that issounded and/or a status icon that is illuminated and that indicates thatperson support apparatus 20 may be hazardous for occupants in generaland/or hazardous for specific occupants with a compromised healthstatus. When an audible signal is used, it may be used alone or incombination with a visual indicator to communicate the usability statusof person support apparatus 20. In one example, the output signalgenerated at 210 is stored by server 66 for later review and/oranalysis.

In some embodiments, algorithm 200 utilizes information from multiplegroups of chemical sensors 50 a that are configured to detect theconcentration of different chemicals over time. For example, a firstgroup of chemical sensors 50 a outputs a signal indicative of theconcentration of a first VOC (or first class of VOCs) over time and asecond group of chemical sensors 50 a outputs a signal indicative of theconcentration of a second VOC (or second class of VOCs) over time. Atstep 208, controller 58 compares the output signals from both the firstand second group of chemical sensors 50 a to reference data relevant tothe respective first and second VOCs. Controller 58 determines theusability status based on the comparison with the reference data forboth the first and second group of chemical sensors 50 a. The referencedata indicates a minimum concentration of each of the first and secondVOCs over a predetermined period of time. If the comparison indicatesthat one or both of the first and second VOCs does not satisfy theminimum concentration for the predetermined period of time, controller58 outputs a signal indicating that person support apparatus 20 is notcleaned or is not sufficiently cleaned. If the comparison indicates thatthe concentration of both the first and second VOCs satisfies thecorresponding minimum concentration for the predetermined period oftime, controller 58 outputs a signal indicating that person supportapparatus 20 is cleaned or sufficiently cleaned.

In one example, the first VOC is present in a first cleaning agent thatis used in a first cleaning stage and the second VOC is present in asecond cleaning agent that is used in a second cleaning stage.Controller 58 uses the presence of both the first and second VOCs todetermine that both the first and second cleaning stages were performedaccording to protocol. In another example, the first and second VOCs arepresent in the same cleaning agent. When present in the same cleaningagent, the first and second VOCs may have different dissipation ratesthat are used by controller 58 to determine that the cleaning agent wasapplied in both the correct concentration and for the correct amount oftime. Alternatively, the first and second VOCs may be present in thesame cleaning agent and, regardless of their dissipation rates,controller 58 uses the presence of both VOCs to distinguish the desiredcleaning agent from other cleaning agents that may have only one or noneof the VOCs. In other words, the two different VOCs that are detectedare chosen as being indicative of a specific cleaning agent or class ofcleaning agents that excludes one or more undesired or unapprovedcleaning agents. By adding even more chemical sensors 50 a, confirmationof the use of a specific cleaning agent can be detected with greaterreliability. Chemicals other than VOCs, such as a marker chemical, areusable in a similar manner in order to detect a specific chemicalsignature of the desired cleaning agent.

In some embodiments, algorithm 200 utilizes output from additionalsensors, such as humidity sensor 50 b, in addition to chemical sensor 50a in determining a usability status of person support apparatus 20. Thisinformation may be used alone or in combination with cleaning profile300 to determine the usability status. In one embodiment, humidity datafrom humidity sensor 50 b is used to provide information regarding thecleaning status and/or the air quality of person support apparatus 20.Algorithm 200 includes an additional step 203 of detecting the humidityadjacent person support apparatus 20 and outputting a signal indicativeof the humidity at step 207. Controller 58 receives the output signalsfrom chemical sensor 50 a and humidity sensor 50 b indicative of the VOCconcentration and humidity, respectively, over time. The output signalsare compared at step 208 with reference data for determining a usabilitystatus. The reference data includes a range or threshold of VOCconcentration compared to humidity that is indicative of a usabilitystatus. At step 210 controller 58 outputs the results from itscomparison of the VOC and humidity levels. At step 212, one or moreusability status indicators are updated and/or changed based on thesignals output at step 210.

Referring now to FIG. 7, graph 320 illustrates three example scenariosdetermined using output signals from chemical sensor 50 a and humiditysensor 50 b. At step 208, controller 58 compares the VOC and humiditysensor output signals with the reference data. If the VOC and humiditysensor output signals satisfy a predetermined threshold, as illustratedby curve 322, controller 58 generates an output signal at 210 indicatingthat the surface has been cleaned or sufficiently cleaned. If the VOCand humidity output signals are below the predetermined threshold, asillustrated by curve 324, controller 58 generates an output signal at210 indicating that the surface has not been cleaned or sufficientlycleaned. For example, if the VOC concentration is too low, cleaning maynot have occurred to the desired degree. In addition, some amount ofwater is required to destroy certain bacteria, and thus a low humiditymay suggest that not enough water was used to destroy water-sensitivebacteria. Curve 324 is illustrative of a scenario in which water wasspilled or used alone for cleaning, or a scenario in which theVOC-containing solution was diluted with too much water. A low VOCconcentration or undetected VOC concentration is also indicative ofscenarios in which the wrong cleaning solution was used, such as ableach or soap solution being used.

If the VOC and humidity sensor output signals are above thepredetermined threshold or range, such as illustrated by curve 326 (FIG.7), controller 58 generates an output signal at step 210 indicating thatthe surface has not been cleaned or sufficiently cleaned. Curve 326 isillustrative of a scenario in which the VOC-containing cleaning solutionwas not diluted enough or not rinsed with enough water, as demonstratedby the low humidity readings. Such a scenario is indicative of thesurface not being properly cleaned and/or indicative of a scenario inwhich person support apparatus 20 is not ready for use by an occupant. Ahigh concentration of VOCs and low humidity may be an indicator of anair quality status that could be of concern for occupant's having acompromised health status, such as a compromised respiratory status or acompromised allergy status. Thus, in one embodiment, if controller 58determines the VOC and humidity output signals are above a predeterminedVOC vs humidity threshold or range, controller 58 generates an outputsignal at 210 indicative of person support apparatus 20 not being readyfor use and/or being a potential hazard for an occupant having acompromised health status.

In another example, in addition to detecting VOCs, chemical sensor 50 adetects other chemical compounds present in the air adjacent personsupport apparatus 20. Algorithm 200 is then used in the same manner asdescribed above regarding VOCs to determine the usability status ofperson support apparatus 20 based on the presence and/or concentrationof the particular chemical compounds detected by chemical sensor 50 a.In one example, the cleaning agent used to clean person supportapparatus 20 includes a marker chemical that is detectable by thechemical sensor 50 a. The marker chemical is a chemical that is added tothe cleaning agent to identify the cleaning agent. In another example,the chemical sensor 50 a is configured to detect a fragrance present inthe cleaning agent used to identify the cleaning agent. In oneembodiment, a change in concentration or presence of the marker chemicalor fragrance over time is used to determine the cleaning status ofperson support apparatus 20 in a manner similar to what is describedabove for algorithm 200 with respect to FIG. 6. In another embodiment, achange in concentration or presence of the marker chemical or fragranceover time compared to the detected humidity is used to determine thecleaning status of person support apparatus 20 in a manner similar towhat is described above for algorithm 200 with respect to FIG. 7. Instill another example, the marker chemical or fragrance is used todetermine that a particular cleaning agent was used.

In still another embodiment, a first group of chemical sensors 50 a isadapted to detect VOCs and a second group of chemical sensors 50 a isadapted to detect one or more particular chemical compounds, such as amarker chemical. The signal output from the first group of chemicalsensors 50 a regarding the VOC concentration is used in the same manneras described above in algorithm 200 to determine the usability status ofperson support apparatus 20. In this embodiment, algorithm 200 includesan additional step between steps 208 and 210 in which the output signalfrom the second group of chemical sensors 50 a is used by controller 58to determine that the correct cleaning agent was used based on thepresence of a predetermined marker chemical detected by the second groupof chemical sensors 50 a. The output signals from both the first andsecond group of chemical sensors 50 a are used at step 210 to determinethe usability status. In this manner algorithm 200 uses the chemicalsensors 50 a, and optionally humidity sensor 50 b, to determine thatperson support apparatus 20 was cleaned to a predetermined degree butalso using a predetermined chemical agent.

In another example, algorithm 200 uses information from temperaturesensor 50 d at 207 to determine the usability status. Certaincombinations of cleaning chemicals may react endothermically, reducingthe air and/or surface temperature, or exothermically, increasing theair and/or surface temperature. The air and/or surface temperature mayalso decrease during evaporation of a solvent of the cleaning solutionused to clean person support apparatus 20, such as an alcohol solvent.In one example, temperature sensor 50 d is an air temperature sensor andchanges in the air temperature are used at 208 to determine if thecorrect cleaning solution was used. In another example, temperaturesensor 50 d is a non-contact temperature sensor, such as an infraredtemperature sensor, and changes in the surface temperature are used at208 to determine if the correct cleaning solution was used. Controller58 includes reference data corresponding to threshold temperature dataor rate of temperature change that is compared to the detectedtemperature at 208 to determine if the correct cleaning solution wasused. This information is used alone or in combination with the chemicalsensor information to determine the usability status of person supportapparatus 20, as described above.

In some embodiments, information from chemical sensor 50 a, humiditysensor 50 b, and temperature sensor 50 d, is used to provide a cleaningsolution profile or “fingerprint”. Controller 58 includes storedcleaning solution fingerprints for comparison with the detectedcharacteristics. If the detected fingerprint matches one of the stored,acceptable fingerprints, the output signal at 210 indicates that thecorrect cleaning solution was used and a corresponding indicator isactivated at 212. If the detected fingerprint does not match one of thestored, acceptable fingerprints, the output signal at 210 indicates thatthe correct cleaning solution was not used and a corresponding indicatoris activated at 212. In one example, the acceptable cleaning solutioncorresponds to a prospective occupant of person support apparatus 20. Ifthe prospective occupant has a compromised health status, such asrespiratory challenges, controller 58 uses the cleaning solutionfingerprint to determine whether the cleaning solution used to cleanperson support apparatus 20 is safe for an occupant with respiratorychallenges. Different cleaning protocols may be associated withdifferent cleaning solutions based on the previous use of personssupport apparatus 20 and/or the future use of person support apparatus20. The cleaning solution fingerprint is used by controller 58 todetermine if the correct cleaning solution was used based on theparticular cleaning protocol.

In another embodiment, information from temperature sensor 50 d is usedto calibrate the data from the chemical sensor 50 a and/or humiditysensor 50 b and is not directly used to determine a characteristic ofthe cleaning agents used during the cleaning process.

In still another embodiment, algorithm 200 utilizes information from oneor more contact pressure sensors 70 to determine the usability status.Pressure sensors 70 provide information regarding physical aspects ofthe cleaning process based on the pressure applied to the surfaces ofperson support apparatus 20 by the cleaning person and/or a tool used bythe cleaning person. Pressure sensors 70 are coupled to support deck 30and/or the cushion (not shown) that forms a support surface for anoccupant of person support apparatus 20 and are adapted to detect apressure applied to support deck 30 and/or the cushion. In thisembodiment, initiation of the usability status process at 202 causescontroller 58 to monitor the signals from pressure sensors 70. Thesignals from pressure sensors 70 are utilized in the manner disclosed incommonly assigned U.S. Pat. Publication No. 2016/0148485 filed Nov. 20,2015, by Hayes et al. and entitled SYSTEM AND METHOD OF MANAGING THECLEANING OF A MEDICAL APPARATUS, to determine whether the appliedpressure during the cleaning process indicates that the physical act ofthe cleaning process was acceptable. Controller 58 uses the informationregarding the physical act of the cleaning process, in addition toinformation received from sensors 50 a-d, to output a signal indicativeof the usability status at 210.

In one example, if the data from pressure sensors 70 indicate thephysical act of the cleaning process was acceptable and the data fromchemical sensors 50 a indicates the cleaning process was acceptable,controller 58 outputs a signal at 210 indicating person supportapparatus 20 is cleaned and/or ready for use. If the data from pressuresensors 70 indicates the physical act of the cleaning process wasunacceptable, even though the data from chemical sensors 50 a indicatesthe cleaning solution was acceptable, controller 58 outputs a signal at210 indicating that person support apparatus 20 is not cleaned and/ornot ready for use. Optionally, controller 58 outputs a signal at 210indicating that the physical act of the cleaning process wasunacceptable and should be repeated. If the data from pressure sensors70 indicates that the physical act of the cleaning process wasacceptable, but the data from chemical sensors 50 a indicates that thecleaning solution was not correct, controller 58 outputs a signal at 210indicating that person support apparatus 20 is not cleaned and/or notready for use. Optionally, controller 58 outputs a signal at 210indicating that the chemical solution used in the cleaning process wasunacceptable and should be repeated or remade.

Referring now to FIG. 8, another algorithm 400 is depicted fordetermining a usability status of person support apparatus 20. Algorithm400 differs from algorithms 100 and 200 in that algorithm 400 utilizesoutputs from ambient air pressure sensor 50 c. Algorithm 400 is usedalone or in combination with any of steps of algorithms 100 and/or 200described herein. Following initiation of algorithm 400 at step 402,which may be triggered in the same manners discussed above fortriggering algorithm 100, air pressure sensor 50 c is activated to begindetecting the local air pressure. Air pressure sensor 50 c detects thelocal air pressure at step 404 through a single reading or multiplerepeated readings. At step 406 air pressure sensor 50 c outputs a signalindicative of the local air pressure to controller 58.

Controller 58 compares the output signal to reference data at step 408to determine a status of person support apparatus 20 based on thedetected pressure. The reference data relates the output signal from airpressure sensor 50 c to one or more predetermined statuses of personsupport apparatus 20. The statuses may correspond to an elevation ofperson support apparatus 20, such as floor in a building, and/or apressure-related event, such as being located in a particular area of ahealthcare facility wherein negative or positive gauge pressure ismaintained for infection control purposes, or for other purposes. In oneexample, the reference data is in the form of a look-up tableidentifying output signals, or ranges of output signals, correspondingto predetermined elevations within a building in which person supportapparatus 20 is located. In such embodiments, controller 58 uses thiscomparison to determine a floor on which person support apparatus 20 iscurrently located within the building. In some instances, the buildinghas one or more designated cleaning areas that are located on one ormore specific floors of the building, and this information is stored aspart of the reference data. Controller 58 then determines whether or notperson support apparatus 20 has been, or is, on a floor in which acleaning area is located. If not, it does not display an indication thatperson support apparatus 20 has been cleaned. If so, it displays anindication that person support apparatus 20 has been cleaned if theother criteria discussed above with respect to algorithms 100 and/or 200are met (e.g. VOC levels are detected above a threshold for apredetermined amount of time).

In some embodiments, controller 58 repeatedly monitors the ambient airpressure readings in order to differentiate fluctuations in pressurebased on weather-related changes from those changes in air pressurerelated to changes in elevation. Changes in elevation due to personsupport apparatus 20 being moved to a different floor of a buildingoccur rapidly, as compared to air pressure changes due to weather.Controller 58 therefore concludes that person support apparatus 20 haschanged elevation by one or more floors if the detected air pressurechanges at a rate greater than a stored threshold. Changes in airpressure that occur more slowly than the stored threshold, or adifferent threshold, are determined to be weather related and are notdue to elevation changes. By keeping track of changes in air pressurethat occur rapidly due to elevation changes, and by knowing the initialfloor on which person support apparatus 20 is located (which may becommunicated to controller 58 via user interface 62 or 68), controller58 is able to continuously determine which floor person supportapparatus 20 is located on.

In some situations, the reference data is in the form of a thresholdthat indicates person support apparatus 20 has been in a particularlocation and/or gone through a process in which the air pressurechanges. The threshold may be in the form of a predetermined change inair pressure over time, a minimum air pressure, or a maximum airpressure. Controller 58 uses this information to determine if personsupport apparatus 20 has gone through a cleaning process that indicatesperson support apparatus 20 is ready for use. Alternatively, controller58 uses this information to determine that person support apparatus 20was used in a restricted area, such as an infectious disease area, andthus is not ready for use.

Controller 58 outputs a signal indicative of the usability status ofperson support apparatus 20 at step 410 based on the comparison betweenthe output signal and the reference data at 408. The output signal atstep 410 activates an indicator at step 412 that communicates theusability status with a user through user interface 62 and/or remoteinterface 68. Step 412 may involve the same processes, or be inaccomplished in any of the same manners, discussed above with respect tosteps 112 and/or 212. Non-limiting examples of indicators activated atstep 412 include illuminable status icons, colored lights, and/or adisplay screen. The indicator may provide information regarding theusability status, the sensed ambient air pressure, the elevation status,and/or pressure-related events.

In another embodiment, algorithm 400 determines that person supportapparatus has experienced a predetermined pressure-related event. In oneexample, the pressure-related event corresponds to entering and/orleaving a designated area. In another example, the pressure-relatedevent corresponds to a cleaning process that involves a change inpressure. For example, an infectious disease control room is typicallykept at a negative pressure compared to the surrounding rooms while aclean room is kept at a positive pressure. If the output signal from airpressure sensor 50 c indicates a rapid change in air pressure above orbelow a predetermined threshold, controller 58 outputs a signal at 410indicating that person support apparatus 20 has entered one of thesedesignated areas.

In one example, if the air pressure signal indicates that person supportapparatus 20 has entered an infectious disease control room, controlsystem 54 saves this information for later use in determining thecleaning needs of person support apparatus 20. In one embodiment, thisinformation is used to determine the cleaning protocol for use incleaning person support apparatus 20 and the reference data foralgorithm 200 is set accordingly. For example, the cleaning protocolfollowing use in an infectious disease control room may require aspecific cleaning protocol, e.g. predetermined humidity, time,temperature, and pressure, using particular cleaning agents and thereference data for algorithm 200 is set based on the protocol and theparticular cleaning agents.

In some healthcare facilities, the cleaning area may be maintained at aparticular ambient air pressure. In such situations, person supportapparatus 20 can be configured to detect if the air pressure signalindicates that person support apparatus 20 has entered such a cleaningroom. If so, controller 58 may generate a signal indicating the presenceof person support apparatus 20 in the cleaning area. Alternatively, oradditionally, controller 58 is configured to monitor the air pressureover time and compare the monitored air pressure to reference dataindicative of a cleaning process within the clean room. For example, adecrease in pressure below a predetermined threshold for a predeterminedperiod of time corresponds to person support apparatus 20 havingremained in the cleaning area long enough to be properly cleaned. If themonitored air pressure and the monitored VOC levels (and/or otheroutputs from sensors 52) satisfy their corresponding thresholds for therequisite periods of time, controller 58 activates an output signalindicating person support apparatus 20 is clean or ready for use. If themonitored air pressure does not satisfy the pressure threshold for apredetermined period of time, or the VOC levels are insufficient,controller 58 activates an output signal indicating person supportapparatus 20 is not clean or is not ready for use. Optionally,controller 58 outputs a signal indicating the cleaning process should berepeated. The information regarding usability status based on the airpressure may be stored by control system 54 for later display and/oranalysis.

In some embodiments of person support apparatus 20, controller 58includes training information as part of algorithms 100, 200, or 400.The training information provides feedback to the personnel responsiblefor cleaning person support apparatus 20. Thus, for example, if acleaning person begins cleaning person support apparatus 20 but sensor50 never detects VOC levels above the minimum concentration required,controller 58 may be configured to provide aural or visual feedback tothe cleaner indicating to them that not enough cleaning agent has beenused. Alternatively, or additionally, if the person support apparatus 20includes contact pressure sensors 70 that do not detect contact pressurebeing applied to all of the surfaces that are desirably cleaned,controller 58 may provide aural or visual feedback to the cleanerinstructing him or her that one or more surface areas have not beencleaned. Such feedback helps ensure that cleaning standards aremaintained uniformly in a healthcare facility, regardless of thedifferent individuals who may carry out the cleaning tasks at differenttimes.

Control system 54 may be configured to use algorithms 100, 200, and 400in any combination to monitor, track, provide feedback and/or train auser regarding a usability status of a person support apparatus.Algorithms 100, 200, and 400 may be used to provide informationregarding usability status of a person support apparatus in real-timeand/or information may be saved over time and analyzed. While only asingle person support apparatus 20 is illustrated, it will be understoodthat multiple person support apparatuses 20 will typically be incommunication with network server 66, with each person support apparatus20 providing information regarding its respective usability status tonetwork server 66.

In one embodiment, usability status determined according to algorithms100, 200, and/or 400 is stored on network server 66 and accessible by auser through remote interface 68 or user interface 62. In one example,the saved usability status information is searchable so that a user maylook up information regarding a particular person support apparatus 20.Non-limiting examples of information that may be searched includesinformation regarding the last time the particular person supportapparatus 20 was cleaned, what it was cleaned with, whether it wasdeemed a hazard for an occupant having a compromised health status, andit's previous location. In one example, a healthcare worker searchesthis information prior to assigning an occupant to the particular personsupport apparatus 20.

In another embodiment, the usability status information is analyzed byadditional applications to track a variety of information. For example,the usability status information may be saved and analyzed to determinehow often each person support apparatus 20 is cleaned or how often eachperson support apparatus 20 is insufficiently cleaned, not suitable foruse, or not safe for use by occupants with a compromised health status.In another example, the usability status information is used to trackhow often the incorrect cleaning solution or concentration of cleaningsolution is used. In still another example, the usability statusinformation is used to track where each person support apparatus 20travels in the building in which they are located. The types of studiesare customizable according to the interests of the healthcare facilityand/or third party, or according to the interests of a group ofhealthcare facilities. Such studies might include, for example:correlations between the usability status and clinical outcomes;housekeeping procedure studies; or infection control studies.

Various additional alterations and changes beyond those alreadymentioned herein can be made to the above-described embodiments. Thisdisclosure is presented for illustrative purposes and should not beinterpreted as an exhaustive description of all embodiments or to limitthe scope of the claims to the specific elements illustrated ordescribed in connection with these embodiments. For example, and withoutlimitation, any individual element(s) of the described embodiments maybe replaced by alternative elements that provide substantially similarfunctionality or otherwise provide adequate operation. This includes,for example, presently known alternative elements, such as those thatmight be currently known to one skilled in the art, and alternativeelements that may be developed in the future, such as those that oneskilled in the art might, upon development, recognize as an alternative.Any reference to claim elements in the singular, for example, using thearticles “a,” “an,” “the” or “said,” is not to be construed as limitingthe element to the singular.

What is claimed is:
 1. A patient support apparatus system comprising:(1) a plurality of patient support apparatuses, each of the patientsupport apparatuses comprising: (a) a support surface adapted to supporta patient thereon; (b) a litter frame adapted to support the supportsurface; (c) a volatile organic compound (VOC) sensor adapted to detectvolatile organic compounds (VOCs) applied to the respective patientsupport apparatus; (d) a controller in communication with the volatileorganic compound sensor and adapted to determine if the respectivepatient support apparatus has been sufficiently cleaned, insufficientlycleaned, or not cleaned based on both a level of VOCs detected by theVOC sensor and a length of time the VOCs are detected by the VOC sensor;(e) a transceiver adapted to transmit data indicating whether therespective patient support apparatus has been sufficiently cleaned,insufficiently cleaned, or not cleaned; and (2) a server incommunication with a user interface and with the transceivers of theplurality of patient support apparatuses, the server adapted to receiveand save the data, and to enable a user of the user interface to searchthe saved data to look up whether a particular one of the plurality ofpatient support apparatuses has been sufficiently cleaned,insufficiently cleaned, or not cleaned.
 2. The patient support apparatussystem of claim 1 wherein the server is further configured to save atime at which the data is received from each of the plurality of patientsupport apparatuses and to enable the user of the user interface to lookup the last time the particular one of the plurality of patient supportapparatuses was sufficiently cleaned.
 3. The patient support apparatussystem of claim 1 wherein the server is further configured to save atime at which the data is received from each of the plurality of patientsupport apparatuses and to enable the user of the user interface to lookup the last time the particular one of the plurality of patient supportapparatuses was insufficiently cleaned.
 4. The patient support apparatussystem of claim 1 wherein the respective VOC sensor of each of theplurality of patient support apparatuses is adapted to detect a markerchemical within a cleaning solution intended to be used for cleaning theplurality of patient support apparatuses, and the respective controllerof each of the plurality of patient support apparatuses is adapted totransmit additional data to the server indicating whether the chemicalmarker was detected or not for the respective patient support apparatus.5. The patient support apparatus system of claim 4 wherein the server isfurther configured to display the additional data indicating whether themarker chemical was detected or not for the particular one of thepatient support apparatuses.
 6. The patient support apparatus system ofclaim 1 wherein each of the plurality of patient support apparatusesfurther comprise a humidity sensor adapted to detect a humidity leveladjacent the respective patient support apparatus, and the respectivecontroller of each of the plurality of patient support apparatuses isfurther adapted to use the humidity sensor to determine if therespective patient support apparatus has been sufficiently cleaned,insufficiently cleaned, or not cleaned.
 7. The patient support apparatussystem of claim 1 wherein the server is further configured to storelocation information for each of the plurality of patient supportapparatuses, the location information indicating a previous location ofeach of respective patient support apparatus prior to being cleaned. 8.The patient support apparatus system of claim 1 wherein each of theplurality of patient support apparatuses further comprises a pressuresensor adapted to detect a contact pressure applied to the supportsurface, and wherein the respective controller of each of the pluralityof patient support apparatuses is further adapted to use the pressuresensor to determine if the respective patient support apparatus has beensufficiently cleaned, insufficiently cleaned, or not cleaned.
 9. Thepatient support apparatus system of claim 1 wherein each of theplurality of patient support apparatuses further comprises an ambientair pressure sensor adapted to detect a pressure of ambient air adjacentthe respective patient support apparatus, and wherein the respectivecontroller of each of the plurality of patient support apparatuses isfurther adapted to forward readings from the respective ambient airpressure sensor to the server.
 10. The patient support apparatus systemof claim 9 wherein the server is adapted to use the readings from theambient air pressure sensors to determine locations of the patientsupport apparatuses.
 11. The patient support apparatus system of claim 1wherein the controller of each of the plurality of patient supportapparatuses is further adapted to use the VOC sensor to determine if ahazardous air condition exists at the respective patient supportapparatus, and the respective controller of each of the plurality ofpatient support apparatuses is further adapted to transmit additionaldata to the server indicating the existence or non-existence of thehazardous condition at the respective patient support apparatus.
 12. Thepatient support apparatus system of claim 11 wherein the server isfurther adapted to track where each of the plurality of patient supportapparatuses travels within a healthcare facility.
 13. The patientsupport apparatus system of claim 11 wherein each of the plurality ofpatient support apparatuses further comprises a temperature sensoradapted to detect a temperature of ambient air adjacent a surface to becleaned on the respective patient support apparatus, and wherein therespective controller of each of the plurality of patient supportapparatuses is further adapted to use the temperature of the ambient airto determine if the respective patient support apparatus has beensufficiently cleaned, insufficiently cleaned, or not cleaned.
 14. Apatient support apparatus system comprising: (1) a plurality of patientsupport apparatuses, each of the patient support apparatuses comprising:(a) a support surface adapted to support a patient thereon; (b) a litterframe adapted to support the support surface; (c) an ambient airpressure sensor adapted to detect ambient air pressure at the patientsupport apparatus; (d) a controller in communication with the ambientair pressure sensor and adapted to determine location data from theambient air pressure sensor; (e) a transceiver adapted to transmit thelocation data; and (2) a server in communication with a user interfaceand with the transceivers of the plurality of patient supportapparatuses, the server adapted to receive and save the location data,and to enable a user of the user interface to search the saved data tolook up the location data for a particular one of the plurality ofpatient support apparatuses.
 15. The patient support apparatus system ofclaim 14 wherein the location data indicates which floor of a healthcarefacility in which the patient support apparatus system is installed. 16.The patient support apparatus system of claim 14 wherein the locationdata indicates a location of a healthcare facility having positive ornegative air pressure.
 17. The patient support apparatus system of claim14 wherein each of the plurality of patient support apparatuses furthercomprise a volatile organic compound (VOC) sensor adapted to detectvolatile organic compounds (VOCs) applied to the respective patientsupport apparatus, and wherein the respective controller of each of theplurality of patient support apparatuses is further adapted to determineif the respective patient support apparatus has been sufficientlycleaned, insufficiently cleaned, or not cleaned based on a level of VOCsdetected by the respective VOC sensor.
 18. The patient support apparatussystem of claim 17 wherein the respective controller of each of theplurality of patient support apparatuses is further adapted to determinea length of time the VOCs are detected by the VOC sensor and to use thelength of time when determining if the respective patient supportapparatus has been sufficient cleaned, insufficiently cleaned, or notcleaned.
 19. The patient support apparatus system of claim 18 whereineach of the transceivers is further adapted to transmit to the serverdata indicating whether the respective patient support apparatus hasbeen sufficiently, insufficiently cleaned, or not cleaned; and theserver is further adapted to receive and save the data, and to enable auser of the user interface to search the saved data to look up whetherthe particular one of the plurality of patient support apparatuses hasbeen sufficiently cleaned, insufficiently cleaned, or not cleaned. 20.The patient support apparatus system of claim 19 wherein the respectiveVOC sensor of each of the plurality of patient support apparatuses isadapted to detect a marker chemical within a cleaning solution intendedto be used for cleaning the plurality of patient support apparatuses;the respective controller of each of the plurality of patient supportapparatuses is adapted to transmit additional data to the serverindicating whether the marker chemical was detected or not for therespective patient support apparatus; and the server is furtherconfigured to display the additional data indicating whether the markerchemical was detected or not for the particular one of the patientsupport apparatuses.
 21. The patient support apparatus system of claim19 wherein each of the plurality of patient support apparatuses furthercomprise a humidity sensor adapted to detect a humidity level adjacentthe respective patient support apparatus, and the respective controllerof each of the plurality of patient support apparatuses is furtheradapted to use the humidity sensor to determine if the respectivepatient support apparatus has been sufficiently cleaned, insufficientlycleaned, or not cleaned.